Compensation of generators or motors.



No. 698,244. Patented Apr. 22, I902.

I F. G. BAUM.

COMPENSATION OF GENERATORS OB MOTORS.

(Application filed Aug. 30, 1901.

(No Model.)

HIIHHI WITNESSES: w 4.

NrrED STATES ATFENT OFFICE;

FRANK G. BAUM, OF STANFORD UNIVERSITY, CALIFORNIA, ASSIGNOR TO STANLEYELECTRIC MANUFACTURING COMPANY, OF PITTSFIELD, MAS- SACHUSETTS, ACORPORATION OF NEW JERSEY.

COMPENSATION OF GENERATORS OR MOTORS.

SPECIFICATION forming part of Letters Patent No. 698,244, dated April22, 1902.

Application filed August 30, 1901. Serial No. 73,818. (No model.)

To aZZ whom, it may concern.-

Be it known that I, FRANK G. BAUM, a citizen of the United States,residing at Stanford University,California, (post-office address thesame,) have invented certain new and useful Improvements in theCompensation of Generators or Motors, of which the following is a full,clear, and exact description.

My invention relates to compensation of to generators or motors, and hasfor its object to provide an improved means for compensating analternating-current generator or motor for various changes in loads,both inductive and non-inductive.

r5 The following is a description of a system embodying myinvention,reference being had to the accompanying drawings, in Which Figure 1shows the system diagrammatically, Figs]? and 3 being diagramsillustrating certain actions that take place.

In the drawings, A represents the coils of a two-phasealternating-current generator; N and S, its two field-magnet poles; B,their energizing-coil, and c c c c the collecting-rings,

from which the current is led to the Workcircuits D D.

E is the armature-coil of an exciter, supplying, through its commutatorF and brushes ff, a current to the energizing-coil B.

G is the field-coil of the exciter field-magnet.

H is the field-coil of the compensator fieldmagnet I.

J is the compensator armature-coil, which is connected at one end to acollecting-ring 7c and at the other end to the conducting-seg ments Z Z,on which the commutator-brush L bears. Connected to the brush L is asecond brush M, which bears upon conducting-seg- 40 ments m m,alternating with those marked Z Z and connected electrically to the ring70, on which bears the brush K. The brush K is connected to onecommutator-brush f of the exciter, the compensator-brushes M L beingconnected to one terminal of the exciter fieldcoil, the other end ofwhich is connected to the exciter-brush f.

O is an ammeter, and Vis a voltmeter, for determining the indications asto current and 5 voltage, and P P are translating devices.

The compensator armature and commutafor are mountedon the shaft R of thegenerator A, which carries the collecting-rings c c c c, the compensatorarmature-coil being in the same polar relation as is the main-generatorarmature-coil, that supplies current to its field-magnet.

Because the compensator field-magnet has an alternating magnetizingsystem corresponding in phase to the current of the main 6o generatorand the compensator-armature rotates synchronously there is in thecompensator-armature an electromotive force of twice the frequency ofthe current of the main generator. This is indicated in Figs. 2 and 3,in which T indicates the current of the main generator, andt the electromotive force of the compensator-armature. The segments Z Z of thecompensator-commutator are so arranged that when there is ninety degreeslag in the work-current in the circuit D they will coincide with acomplete half-period of the compensator electro notive force, so thatthe upper halves of each cycle are taken off and impressed upon thecircuit of the exciter field-coil. This is representedin Fig. 2. If,however, there is a lag of any less amount in the work-current, theupper part of a cycle by that much does not coincide with the segments Zand part of an upper half and part of a lower half is impressed upon theexciters energizing-circuit, as represented by the shaded portions inFig. 3, the parts corresponding to the lag or lead present. In this waythe eXciter responds to any lag in the work-circuit and the lag is dulycompensated for. The increased current in the main D due to an increaseof load compensates for any tendency toward a drop because of suchincreased load.

Since the armature-coil of the compensator is in circuit only one-halfthe time, it is necessary to provide means for connecting the brushes,so as to keep the exciter field-circuit complete at othertimes. This isdone by the 5 segments m m, which slightly overlap segments Z Z and areconnected to the ring k. When the brush M is upon a segment m, aconnection is formed directly between the compensator-brushes. 1 oo Inorder to make it unnecessary for the whole Work-current to go throughthe com pensator field-coil II, I provide a shunt U with a means foradjusting the same, so that its time constant shall be the same as thatof the coil H. In this Way the lag in II will always be the same as thelag in the undivided main.

One of the advantages of my system is that by causing the compensator toact upon the exciter it is not necessary to apply a compound winding tothe main-generator magnet, which is expensive and difficult.Furthermore, it is particularly useful where several machines are to becompensated, since the current from the single exciter can be passedthrough all the field-magnets, so that they will all be compensated andcan be compensated When in parallel and for varying power factors. Asimilar arrangement can be used with motors.

Vhat I claim is 1. In a system of distribution the combination of analternatirig-current generator, an exciter therefor, a compensatorenergized by the alternating current in the main-generator circuitleading to the translating devices and energizing in part thefield-magnet of the exciton 2. In a system of distribution thecombination of an alternating-current generator, an exciter therefor,and a compensator energized by the alternating current in themain-generator circuitleading to the translating devices, saidcompensator being in series With the armatures and field-coil of theexeiter.

3. In a system of distribution by alternating currents, a compensatorconsisting of a field-magnet energized by the alternating current in themain leading to the translating devices, an armature rotating relativelythereto, synchronously with the main generator and arectifying-con1mutator, said compensator supplying current to thefield-magnet of an exciter for the main generator.

4. In a system of distribution by alternating currents, a compensatorconsisting of a field-magnet energized by alternating currents in themain leading from the main generator to the translating devices, anarmature rotating relatively thereto, synchronously with the maingenerator and a rectifyingcommutator, having the conducting-segmentscorresponding to one-half of each period removed.

5. In a system of distribution by alternating currents, a compensatorconsisting of a field-magnet energized by the alternating current in themain leading to the translating devices,an armature rotating relativelythereto, synchronously with the main generator and arectifying-commutator, having the conducting-segments corresponding toone-half of each period and means for automatically shunting the brushesthereof when they are not upon the conducting-segments of thecommutator.

Signed at Butte, Montana, this 29th day of July, 1901.

FRAN K G. llrll TM.

\Vitnesses:

PERCY l3. Dawson, RALPH Dawson.

